I'm only recently returned to actually looking at the game and what you can build a force around.

Can someone verify for me that Formations can be taken in any number; but that each formation cannot be composed of overlapping units. IE - For instance a Living Artillery Node (Exocrine, Biovores, Tyranid Warriors) and a Synaptic Swarm (T. Prime and 3 broods of Tyranid Warriors) if taken in the same force would necessitate 4 broods of Tyranid Warriors correct?

It seems like the rules are saying this, but I'm still stuck in an early 6e mindset at best. Thanks.

You can indeed take multiples of the same formation and as many formations as you like. And yes, in the example you gave, you would require 4 broods of Tyranid Warriors. The Living Artillery Node Warriors wouldn't gain the benefits of the Synaptic Swarm and vice versa.